On expanding recombining plasma for fast deposition of a-Si:H thin films

A high-density expanding recombining plasma is investigated for deposition of a-Si: H thin films. The deposition method allows nigh growth rates and it relies on separation of plasma production in a high-pressure thermal arc, and transport of iragments of injected SiH(4) monomer to the substrate. Some characteristics of the plasma are discussed together with an explanation of the dominant chemical kinetics. which proceed mainly through heavy-panicle interactions. The deposition results indeed show very high growth rates from 2-30 nm s(-1) on areas of 30 cm(2). The properties of the layers are characterized by measuring their refractive index ( in the range 3.1-3.8) and bandgap (1.2-1.5 eV). Analysis of the oxygen content in the deposited films shows oxidation of the samples in air, which is probably associated with the microstructure of the layers.